OUE WORN SOILS 71 



without this law of service neither can live. 



The soil is bound by the same law of service and 

 gives up its life elements that plants may live and 

 grow and bear their burden of harvest that they 

 too may render service to man. But soil can not 

 live and render service unless service has been 

 rendered unto it by plants and other fertilizing 

 agencies, so that it may gather the fertility that 

 it gives back in service. 



So in the restoration of worn soils we must sim- 

 ply study the law of service and compensation, and 

 when we do this we find that soils must have or- 

 ganic matter in them to furnish food for soil bac- 

 teria, so that the bacteria may compound and dis- 

 tribute the substances needed for plant food, and 

 cleanse the soil of its offensive accumulations. 

 And soils must have in them the nitrogen to pro- 

 mote the growth of plants and the soil ventilation 

 which is secured by drainage, and by incorporat- 

 ing into it large quantities of organic matter. 

 Organic matter is put into the soil for its use by 

 plowing under of manure, cornstalks, straw or 

 any green manuring crop, or vegetable, or plant 

 residue. 



We have already showed that the first aid to 

 the restoration of worn-out soils is through drain- 

 age drainage constructed with the thought of 

 soils ventilation, and that the next aid is the secur- 

 ing for it an abundance of organic matter. Ma- 

 nure is considered by many the best organic mat- 

 ter, but as it cannot generally be secured in suf- 

 ficient quantities, we must look to other sources 

 for supplies. 



The next best source of securing a supply of 



